Monday, 10 December 2012

Van Veen OCR 1000 - Dutch Wankel Powered Superbike

Over the years the Wankel rotary engine has
been, paradoxically, the best and worst alternative to the good ol’ gasoline
burning, reciprocating piston engine. Felix Wankel’s concept has shown great
promise since its introduction in the 1950s and it has found its way into a
wide variety of vehicles. All of which have ended up as, at best, curiosities.
Which brings us to the Dutch Van Veen OCR-1000 double-rotor superbike, which is
likely one of the best rotary-powered motorcycles, and certainly one of the
rarest.

Rotaries are one of those engineer’s wet
dreams that is full of promise and has the potential to revolutionize an
industry – on paper. It’s light. It’s compact. It’s extremely simple and has
few moving parts. It’s far more efficient in terms of power to displacement and
has far fewer friction losses than a traditional piston driven four-stroke. It
was touted as the future of internal combustion, a better way to burn
hydrocarbons that would render the antiquated reciprocating piston engine
obsolete.

In reality the rotary is indeed a very
efficient design in terms of power vs weight and displacement. A small
displacement Wankel punches well above its weight in terms of power, almost
like a two-stroke (though it depends on who you ask and how they measure the displacement of a rotary - opinions vary). Problem is it is not efficient when
it comes to fuel or oil consumption – that’s where it REALLY punches above its
weight, sucking gas like a far, far bigger engine… with an oil-burning problem.
Economy and clean emissions are not the fortes of the rotary.

Then you get into long-term reliability
issues. While the lack of moving parts and complex systems contributes to
admirable simplicity (engineer’s wet dream, remember), what DOES move sees
significant wear - specifically, the apex (rotor tip) seals, which remain a
major hurdle. The triangular rotor wobbles through an oval chamber, with the
four stroke cycle occurring in the pockets created by the flat sides of the
rotor as it rotates. The tricky bit is keeping the narrow tips of the rotor
sealed against the casing. Up until recently the rotor tips tended to wear
quite quickly, which causes the mixture to leaks between the chambers,
necessitating regular rebuilds. Very careful maintenance and running procedures
are needed to ensure longevity, even in modern rotaries – which are produced
almost exclusively by Mazda, who remained stalwart defenders of the Wankel
until they recently had to stop production due to tightening emissions
standards.

Of course, the whole concept of the rotary
sounds ideal for motorcycles. Sure, it’s not super economical and needs to be
rebuilt semi-regularly – but compared to a two stroke or a high-strung
four-stroke motorbike that’s nothing new. The compact size and high efficiency
of the design makes it ideal for application in a two-wheeled contrivance.

Then there was the Van Veen OCR-1000, arguably the
best rotary motorcycle of the 1970s.

Henk van Veen was the Dutch importer of
Kreidler two strokes, and prepared bikes for the 50cc GP category. He became
well known for his work in Grand Prix racing in the 1970s but yearned for
success in a big-bike category. Thus he began the OCR project in early ‘70s,
with the aim of building a Wankel powered superbike with thoroughly modern
technology. The first prototype used a Moto Guzzi V7 frame mated to a Mazda
rotary engine.

Several factors
were working in Van Veen’s favour. While rotary technology was still relatively
new in the 1960s and 70s, it held a lot of promise and there were many
companies experimenting with the newfangled technology. However, NSU (who
employed Felix Wankel and held the patents on rotaries) maintained strict rules
regarding the design and production of rotaries by outside firms, and demanded
exorbitant royalties from those who wished to build their own rotaries. This
was (part) of the demise of the W2000; the restrictions were relaxed if your design made no more than 30 hp, so the Sachs engine in the W2000 was tuned below that. The RE-5 only made a claimed 62 hp, and weighed
over 550 lbs, which put it behind most four-stroke Superbikes of the 1970s. Up
until Norton started making high performance rotary bikes in the 1980s, you
didn’t pick a Wankel-powered ride for world-beating performance.

Unless you bought an OCR-1000, that is.

After the warm reception of the prototype,
work began on a more polished and advanced production model. The timing
appeared right as well. In the late 1960s NSU and Citroen formed a partnership
to manufacture engine in Luxembourg called Comotor, which was set to build an
advanced liquid-cooled double-rotor engine for the Citroen GS. The engine,
unveiled in 1973, displaced 996cc and pumped out 107hp and an impressive 103
lb/ft of torque in a compact package that weighed just over 200 lbs. It was
designed for light car applications, and was a marked improvement over the
older NSU and Mazda designs. Van Veen saw the potential for it to power his
OCR, and set about obtaining a supply of engines from Comotor.

The OCR was given a restyle and a new
design was built around the Comotor mill, with a Porsche-designed gearbox mated to a drive shaft, and
various modifications to suit a two-wheeled application. The result was a
clean, futuristic bike that was dominated by a massive, matte-finished engine
block. Component quality and finishing was high, and subtle details abounded –
the exhausts featured rectangular exits with bevelled canisters, the fork legs
repeated the rotary logo found on the engine cases, and the bike was suspended
on cast wheels with hydraulic disks front and back (rare at the time). Van Veen
set his sights high, and wanted to build the ultimate superbike in terms of
engineering, performance, and build quality.

So the OCR-1000 looked to be the ultimate
rotary powered motorcycle – it was nice looking, well built, and quite
powerful. There were, however, some issues.

The most notable was the price. It
fluctuated over the years, but was roughly equivalent to 15000$ US. That meant
that, aside from being prohibitively expensive, the OCR would always suffer the
“but the price” reviewer mentality – it was a good bike, but it wasn’t two-BMWs-worth
good and the period reviews were quick to point this out.

It was also heavy - almost 700 lbs. That’s
fine if you are talking about full dress Harleys, but not so much for a
bleeding edge technology bike with sporting intentions.

Then there were the engine issues. Despite
showing great promise the Comotor engine was plagued with issues, both in the
Van Veen and the Citroen it was designed for. The GS Birotor sedan ended up
being a complete failure, with only 874 produced – almost all of which were
bought back and crushed by Citroen so they wouldn’t have to keep producing
spare parts. Comotor would shamble on for a few more years, eventually going
under in 1980.

The Van Veen was more or less finished by
1979, but “production” of a few more bikes continued until 1981. A total of 38
machines were built, and after the company shuttered the tooling and spares
were bought by a Dutch rotary specialist.

But that wasn’t the end of the OCR-1000. In
mid 2011, a surprising announcement was made. Two Dutchmen, Dirk Knip and
Andries Wielinga had bought the mothballed tooling for the OCR and would build
a final run of 10 bikes. Thus the new 2011 Van Veen, same as the old Van Veen,
was born. A brand new-old OCR was yours for the price of 115000$. No I did not
accidentally add a zero. Makes the original 15000$ price tag seem quite
reasonable in comparison.

The 2011 OCR was revealed to the press and
limited demos were offered to a few journalists. Hans Koopman from Motorcycle
Classics magazine had this to say:

Swing a leg over the seat and two things
immediately stand out; the vibration-free rotary engine and the perfect seating
position. The high handlebars combined with the not too high footrests provide
the relaxed attitude you expect from a touring bike. Another surprise is the
bike’s low-speed handling, where the bike’s high weight disappears like snow in
the sun. The handling, even compared to modern bikes, is glorious, much better
than that of big touring bikes of the late 1970s like the Kawasaki KZ1300 or
Yamaha XS1100.

Out on the road, the Van Veen rides almost
like a Honda. Shifting, braking, handlebar switchgear, everything is as you’re
used to on any modern bike. The mirrors are clear, the ground clearance ample,
and you never notice that you’re riding a rotary-powered bike, because the
power packs neatly, just as you expect from a modern four-stroke. The
specifications indicate 100 horsepower, but we didn’t get to use it all. On a
few straights we took the engine to just above 4,000rpm (redline is 6,500rpm),
where the engine starts to reveal its true nature, pulling aggressively.

The review is positive and polite, though
for over one-hundred-thousand bucks you’d hope it was passable. Clearly, the
new OCR is intended as a rare curiosity for the wealthy collector rather than
an attempt to revive Van Veen production. The fact they are only making 10
should indicate that. Some improvements are being incorporated into the motor
in the hopes of eliminating the teething problems of the Comotor unit that
plagued the original series of bikes. In fact you get a two-year warranty, and
spares support. However there are no plans to continue production after the 10th
bike is finished.

The Van Veen started out as an attempt to
build the world’s finest superbike, a rolling engineer’s dream with stunning
performance. In the end it became a curious exercise that showed great promise,
but was plagued by the usual rotary shortcomings and a prohibitive price tag.
Henk van Veen built one of the best rotary powered bikes of all time, but few
were ever able to appreciate the effort, and even then he was unable to
circumvent the problems inherent in early Wankel motors. The 2011 “revival” of
Van Veen motorcycles adds a fascinating footnote to the story, but with a six
figure price tag it doesn’t bring Henk’s concept any closer to the average
rider. So the OCR-1000 remains a classic odd bike – weird, ambitious,
impressive, but ultimately doomed to obscurity.